New York | Robinhood, the trading app at the centre of a frenzy over GameStop and other stocks, raised $US2.4 billion ($3.1 billion) from its investors over the weekend, adding to the $US1 billion cash infusion it took last week as it tries to steady its finances.

The extraordinarily high volume of trading by amateur investors in recent days, many egged on by social media and determined to challenge Wall Street hedge funds, had put a strain on Robinhood’s balance sheet. As an online brokerage firm, the company is required to keep a certain cash cushion to insulate against potential losses, and the required cushion can grow quickly when trading volume and volatility are spiking.